Physical, chemical and biological properties of water
1. THE PHYSICAL, CHEMICAL AND BIOLOGICAL
PROPERTIES OF WATER
BUILDING UTILITIES: PLUMBING AND
SANITARY SYSTEMS
2. ALL LIVING THINGS, FROM THE SMALLEST INSECT NEEDS WATER TO
LIVE. EXPERTS PREDICT THAT BY 2025, 1/3 OF THE WORLDS
POPULATION WILL NOT HAVE WATER DUE TO THE INCREASE IN
POPULATION AND WATER CONTAMINATION.
EACH PERSON DISCHARGE ABOUT 200,000,000,000 COLIFORMS PER
DAY. COLIFORM BACTERIA ARE THEREFORE VERY NUMEROUS-AND
THE MOST COMMON AD WIDESPREAD HEALTH RISK ASSOCIATED
WITH DRINKING WATER IS MICROBIAL CONTAMINATION , THE
CONSEQUENCES OF WHICH MEAN THAT ITS CONTROL MUST ALWAYS
BE OF PARAMOUNT IMPORTANCE.
EARTH CURRENTLY HAS ESTIMATED 6.9 BILLION POPULATION AS OF
JULY 1, 2011 BY THE UNITED STATES CENSUS BUREAU.
3. THE USES OF WATER:
OUR WORLD IS A PLANET THAT IS DOMINATED BY WATER AND THROUGH THE
YEARS THE DEVELOPMENT IN THE STUDY OF WATER HAS BEEN IMPROVED
AND PRACTICALLY TESTED. THERE ARE A LOT OF USES OF WATER AND THE
FOLLOWING ARE JUST A FEW OF IT’S EXAMPLES.
1. THE WATER IS ONE OF THE MOST IMPORTANT SOURCE OF A HUMAN LIFE.
2. WATER IS THE HABITAT OF SEVERAL SPECIES.
3. WATER SERVES AS OUR MAIN COURSE FOR THE HUMAN HYGIENE.
4. WATER IS THE BASE OF ALL DRINKS AND BEVERAGES.
5. ETC.
4. THE WATER AND ITS PROPERTIES
THE PHYSICAL, CHEMICAL AND
BIOLOGICAL PROPERTIES OF WATER
5. PHYSICAL PROPERTIES:
Water has several other unique physical properties. These properties are:
1. Water has a high specific heat. Specific heat is the amount of energy required to
change the temperature of a substance. Because water has a high specific heat, it
can absorb large amounts of heat energy before it begins to get hot.
2. Water in a pure state has a neutral pH. As a result, pure water is
neither acidic nor basic. Water changes its pH when substances are dissolved in it.
6. 3. Water conducts heat more easily than any liquid except mercury. This fact causes
large bodies of liquid water like lakes and oceans to have essentially a uniform
vertical temperature profile.
4. Water molecules exist in liquid form over an important range of temperature
from 0 - 100° Celsius. This range allows water molecules to exist as a liquid in
most places on our planet.
5. Water is a universal solvent.
6. Water has a high surface tension. In other words, water is adhesive and elastic,
and tends to aggregate in drops rather than spread out over a surface as a thin film.
This phenomenon also causes water to stick to the sides of vertical structures
despite gravity's downward pull.
7. CHEMICAL PROPERTIES:
Water’s chemical formula is H2O. The water molecule odd shape with both
hydrogen atoms occurring on the same side of the oxygen atom gives water its
ability to “stick” to itself and to other surfaces. The hydrogen atoms create a
positive electrical charge while the oxygen atom creates a negative charge. The
attraction to one another is what causes water to form droplets. The chemical
properties make water essential to the functioning of living things including human
beings. We must ingest or drink water in order to maintain good health.
8. This model of a water molecule
shows the arrangement of one
oxygen atom bound to two atoms of
hydrogen and their positive and
negative charges.
Arranged water molecules positive
to negative charges make water
“sticky” and from drops or beads on
a smooth surface.
9. Water beads on hood of a car
because of the arrangement of
water molecules.
10. There is a clear correlation between access to safe water
and GDP per capita. However, some observers have
estimated that by 2025 more than half of the world
population will be facing water-based vulnerability. A
recent report (November 2009) suggests that by 2030, in
some developing regions of the world, water demand will
exceed supply by 50%. Water plays an important role in the
world economy, as it functions as a solvent for a wide
variety of chemical substances and facilitates industrial
cooling and transportation. Approximately 70% of
freshwater is consumed by agriculture.
11. CHEMICAL PROPERTIES:
1. pH
2. Alkalinity
3. Total Hardness
4. Iron, Manganese,
5. Metal-Zinc, Copper, Chromium, Lead
6. Nitrate/ Nitrite
7. Arsenic, Fluoride
8. Chloride
9. Total and Free Chlorine
12. STANDARD VALUES FOR INORGANIC CHEMICAL CONSTITUENTS WITH
HEALTH SIGNIFICANCE:
CONSTITUENTS: MAXIMUM LEVEL REMARKS
(mg/L)
ARSENIC 0.05 FOR EXISTING WATER SUPPLY SYSTEM ARSENIC MAY
BE NATURALLY OCCURRING IN WATER SOURCES.
WHERE MAXIMUM LEVEL OF ARSENIC IS
UNACHIEVABLE, CONCENTRATION IN WATER SUPPLY
MUST BE KEPT AS LOW AS POSSIBLE
CADMIUM 0.003 CADMIUM IS USED IN MANUFACTURE OF STEEL,
PLASTICS AND BATTERY AND RELEASE TO THE
ENVIRONMENT THROUGH WASTEWATER OR FUMES.
CADMIUM IS RELEASED IN WATER SUPPLY AS
IMPURITY OF THE ZINC COATING OF GALVANIZED
PIPES AND SOLDERS AND METAL FITTINGS.
LEAD 0.01 LEAD MAY BE PRESENT IN WATER PRIMARILY FROM
PLUMBING SYSTEMS CONTAINING LEAD PIPES,
SOLDER, FITTINGS OR THE SERVICE CONNECTIONS TO
THE HOMES
13. CONSTITUENTS: MAXIMUM LEVEL REMARKS
(mg/L)
NITRATE 50 NITRATE CONCENTRATION IN GROUNDWATER AND
SURFACEWATER CAN REACH HIGH LEVELS AS A RESULT OF
LEACHING OR RUN-OFF FROM AGRICULTURAL LAND OR
CONTAMINATION FROM HUMAN OR ANIMAL WASTES.
ANAEROBIC CONDITIONS MAY RESULT IN THE
FORMATION AND PERSISTENCE OF NITRITE.
NITRITE 3
MERCURY 0.001 MRCURY IS USED IN THE INDUSTRIES SUCH AS IN THE
ELECTROLYTIC PRODUCTION OF CHLORINE, IN ELECTRICAL
APPLIANCES, IN DENTAL AMALGAMS AND AS A RAW
MATERIAL FOR VARIOUS MERCURY COMPOUNDS.
MERCURY OCCURS NATURALLY IN FRESHWATER AND
GROUNDWATER IN THE INORGANIC FORM. METHYLATION
OF INORGANIC MERCURY OCCURS IN FRESHWATER AND
SEAWATER.
CYANIDE 0.07 CYANIDES ARE OCCASIONALLY FOUND IN DRINKING
WATER PRIMARILY AS A CONSEQUENCE OF INDUSTRIAL
CONTAMINATION.
ANTIMONY 0.02 ANTIMONY IS CONTAMINANT FROM PIPE AND FITTING
MATERIALS. IT IS NOT A RAW WATER CONTAMINANT.
14. BIOLOGICAL PROPERTIES:
1. Adhesion: water tends to stick unlike substances . Example is water sticking to
blood vessels.
2. Cohesion: which water molecules clings together due to Hydrogen bonding; the
surface film (top layer of water) is held by surface tension. Example is spilled
water forming a puddle.
3. Solvency: water is considered a universal solvent for its ability to dissolve a
wide range of substance since it is a polar molecule. Example is salt or sugar
dissolving in water.
15. 4. Chemical reactivity: water can participate in chemical reactions. Example:
involvement of water molecules in dehydration synthesis and hydrolysis.
5. Thermal stability: water has a high heat capacity, so it requires a lot of energy to
heat up; requires 1 cal to raise 1 gram of water by 1 degree C. Example: stability of
the ocean's temperature during summer and winter.